The e53 with air felt tighter in the twisties but I can def go faster in the e70 with the springs 35% more HP and torque.
More body roll but softer ride it's an ok trade off.
https://www.icloud.com/sharedalbum/#B0Z5yeZFhU8G6Y
The third to last is prob my favorite. It was snowing out so I wasn't pushing too hard but that's a very fun road.
The air springs are firmer. It was very noticeable on wife's e70 vs. mine. And on our e53 as well (role was reversed I had air in the e53 she had springs).
Once you get into a tight turn it locks in and you can power though the curves regardless coil or air.
I was very happy to have the air in the e53 and I'm about equally happy I accidentally ended up with coil on the e70.